Rep. Mike Coffman (R-Colo.) stumblingly rejected the science of climate change in a debate for his re-election to Colorado’s sixth district on Tuesday. His challenger, Democrat Andrew Romanoff, expressed his confidence that climate change is caused by humans and can be reversed. Visibly uncomfortable, Coffman paused and mumbled his answers to the two questions from the moderators, Denver Post reporters Jon Murray and Chuck Plunkett. Watch the video, courtesy of ColoradoPols.com:

Rep. Coffman does not believe that humans are contributing significantly to climate change, which is already damaging Colorado with increased drought, wildfire, and floods.

In reality, the carbon-dioxide greenhouse effect is a physical fact known since the 1800s. The only scientifically plausible systematic explanation for the rapid and continuing warming of the planetary climate since 1950 is industrial greenhouse pollution. The world’s national scientific societies and the world’s practicing climate scientists are in overwhelming agreement about this fact.